Adjustable bed



FIG. 1 is a left side elevational view of an adjustable bed, showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a bottom plan view thereof; and

FIG. 5 is a view like FIG. 1 of the bed in horizontal position. 

The ornamental design for an adjustable bed, substantially as shown and described. 